How to prevent data from being loaded in NgRx a second time?

I have a DOM block:

<div (click)="toggle(block)">
   <div *ngIf="block.opened">
     <div *ngFor="let item of block.items"></div>
   </div>
</div>

On click I dispatch action to load data from server and display this data in block:

  toggle(block: RegistryGroup) {
    this.store.dispatch(RegistryActions.ToggleRegistryBlockAction(block));
    this.store.dispatch(RegistryActions.LoadRegistryLayersAction(this.block));
  }

The first event ToggleRegistryBlockActionchanges the property blockto true/false. The second LoadRegistryLayersActionmakes a request to the server block.idand returns the data to the same state of blockthe propertyblock.items = Server Response;

Actually, I'm listening to the action LoadRegistryLayersAction:

loadRegistriesLayers$: Observable<Action> = createEffect(() =>
    this.actions$.pipe(
      ofType(RegistryActions.LoadRegistryLayersAction),
      filter(
        (registryGroup) =>
          registryGroup.items && !registryGroup.items.length
      ),
      switchMap((registryGroup: RegistryGroup) =>
        from(this.registry.getRegistryLayers(registryGroup.Id)).pipe(
          map((layers: { [key: string]: RegistryLayerItemGeneric[] }) => {
            return RegistryActions.SuccessLoadRegistryLayersAction({
              payload: {
                layers: this.registry.createLayersMapWithObjects(layers),
                registryGroupId: registryGroup.Id,
              },
            });
          }),
          catchError((error: Error) => {
            return of(RegistryActions.ErrorRegistryLayersAction(error));
          })
        )
      )
    )
  );

I filtertake action and check if the data already exists. For this, I check if the block has registryGroup.items && !registryGroup.items.length.

The problem is that sometimes after executing this effect server it may return empty []. So the next time the user requests it, it will repeat the request.

If the data is already loaded, how can I fix it and not touch the server?